| 摘要 |
A process for producing a film comprising a polyimide having repeating units represented by the following formula (1), which comprises stretching an unstretched polyimide film having an organic solvent content of 0.5-30 wt.%, excluding 30 wt.%, at a temperature of 150-380°C in a stretch ratio of 1.2-4.0. Thus, a polyimide film is obtained which is colorless and transparent, has excellent heat resistance, and is reduced in dimensional change. [Chemical formula 1] (In the formula, R is a tetravalent group derived from cyclohexane and 4 is a divalent aliphatic, alicyclic, or aromatic group or a combination of two or more of such groups and may have as a connecting group at least one member selected from the group consisting of-O-,-SO2-,-CO-,-CH2-,-C(CH3)2-,-OSi(CH3) 2-,-C2H4O-, and-S-, the total number of carbon atoms in 4 being 2-39.) |
